X-ray is widely used in the fields of industrial non-destructive test, safety inspection, medical diagnosis and treatment. In particular, X-ray radiographic imaging devices owing to the high penetration performance of X-rays play an important role in all aspects of people's daily life. These devices were presented as film-based planar fluoroscopic imaging devices previously. At present, these devices with advanced technology are regarded as stereoscopic imaging devices with digital, multi-view; and high-resolution, for example computed tomography (CT), which may acquire high-resolution 3D stereoscopic image or slicing image as an advanced high-end application.
In the existing CT device, the X-ray generating device moves on the slip ring. In order to improve inspecting speed, moving speed of the X-ray generating device is usually quite fast, and thereby decreases reliability and stability throughout the device. In addition, due to limitation of the moving speed, the inspecting speed of the CT is also limited, so that inspection efficiency is lower. Furthermore, the X-ray sources of such devices move on the slip ring to cause focus of the equivalent X-ray sources larger such that the imaged pictures have motion artifacts and poor in the imaged images, poor resolution, and there is a possibility of missing inspection for some smaller contrabands. Besides, such devices may only inspect stationary (or slow-moving) objects but almost cannot form a three-dimensional image for the moving object.
Hot cathodes serve as electronic emission units and are arranged in array. The voltage between the hot cathode grids is used to control emission of electrons so as to control each cathode to emit electrons in sequence and to bombard target points on the anodes in the corresponding sequence, to establish an arranged X-ray source. By using an electronic switch instead of mechanical rotation of a spiral CT, the X-ray source may be rapidly generated from many views to rapidly image in different angles. This method may greatly improve inspection efficiency and enhance sharpness of the images. And, this scheme structure is simple, the system is stable and the reliability is higher.
In order to improve imaging quality of arranged light sources, it is generally required that light sources from the arranged light source are determined in a range of several tens to hundreds (as required), which means that a large amount of cathodes are required. The current design scheme is provided such that the cathode, a beam control electrode (grid), a compensation focus electrode is integrated together, if one of the cathodes (or cathode assembly) malfunctions, detaching and replacing are very complicated. Thus, the current design scheme is very inconvenient in terms of maintenance and replacement of an equipment.
The contents as above disclosed in this background are only employed to enhance understanding the technical background of this disclosure, thereby the existing knowledge that are not well-known for those skilled in the art may be included in this disclosure.